Fan apparatus, method of manufacturing fan apparatus, projection type display device and electronic device

ABSTRACT

With a trend toward a higher intensity projection type liquid crystal display device to further increase brightness of a projection screen, rated input power of a light source lamp increases, which makes essential a fan apparatus for cooling the light source lamp, etc. Such a fan apparatus would require a light-shielding member which causes the number of parts to increase. The present invention provides a fan apparatus provided with a rotor section that can be rotated/driven around a predetermined rotation axis and a propeller section including propeller blades and attached to the rotor section arranged in such a way as to substantially shield light parallel to the rotation axis.

THIS APPLICATION IS A U.S. NATIONAL PHASE APPLICATION OF PCTINTERNATIONAL APPLICATION PCT/JP02/08637.

TECHNICAL FIELD

The present invention relates to a fan apparatus, method ofmanufacturing the fan apparatus, projection type display device andelectronic device applicable for the purpose of cooling an electronicdevice such as a projection type display device. The projection typedisplay device may be of the kind that decomposes white light from alight source lamp into light beams of three colors; red, blue and green,and lets each light beam pass through a light bulb composed of, forexample, a liquid crystal panel. The light beams are then modulatedaccording to image information, color-combined after modulation and thenenlarged and projected onto a screen through a projection lens unit.

BACKGROUND ART

For a projection type liquid crystal display device in recent years, ahigh resolution light bulb device, for example, a liquid crystal panelunit is used to project image information more clearly and brightness iscontinuously increased to light up the projection screen brighter.

More specifically, with the widespread use of personal computers such asnotebook personal computers, there is a strong demand for a small, lightprojection type display device with excellent portability as an imageoutput apparatus for a notebook personal computer which is widely usedfor electronic presentations. Furthermore, a projection type displaydevice, etc., for a home theater is also becoming widespread.

On the other hand, as the brightness increases, rated input power of alight source lamp also increases, which makes it more important tosecure cooling performance for cooling the light source lamp, etc.

With reference now to FIGS. 5 to 7, a conventional projection typed isplay device will be explained. FIG. 6 is a plan view of a conventionalprojection type display device using a cooling apparatus around a lightsource lamp used in a projection type display device that modulateslight signals through a light bulb made up of a liquid crystal panelaccording to image information, color-combines modulated light beams ofdifferent colors after modulation, enlarges and projects the light beamson a screen through a projection lens unit. Furthermore, FIG. 7 is aright side view of the same device. FIG. 5 illustrates a conventionalaxial flow fan to show an overview of a cooling fan 6 which is a generalaxial flow fan used in the same device.

As shown in FIG. 6, the conventional projection type display deviceincludes a light source lamp unit 1, an irradiation optical unit 2 thatcondenses light from the above-described light source lamp unit 1, threeliquid crystal panel units 3 consisting of R, G and B liquid crystalpanels as light bulbs for optically generating image information fromthe condensed light, a color combination system unit 4 thatcolor-combines the optical information of the liquid crystal panel units3, a projection optical unit 5 that enlarges and projects the imageinformation onto a screen, a cooling fan 6 for cooling the light sourcelamp unit 1 and its periphery, a light-shielding member 7 for preventingunnecessary light of the light source lamp unit 1 from leaking outwardand a housing 8 provided with a exhaust opening 9 for circulatingexhaust air of the cooling fan 6.

Here, the cooling mechanism of such a projection type display devicewill be explained.

As shown in FIG. 6, the high temperature atmosphere of the light sourcelamp unit 1 is led through the light-shielding member 7 and exhaustedout of the housing through the exhaust opening 9 provided in the housing8 due to a pressure difference produced before and after propellers asair blowing means by rotation of the cooling fan 6. In this way, theheat of the atmosphere inside the housing 8 is transferred and coolingis realized.

More specifically, propellers 12 form an air blowing means formedintegral with the rotor of a motor 11 and rotate as the motor 11rotates. Thus, the air is circulated in the axial direction inside anair duct formed in a housing 10 that holds the motor generally alignedwith the rotation center of the motor 11.

However, such a conventional projection type display device requires alarge light-shielding member to prevent light from leaking toward theoutside of the set through the exhaust opening that circulates exhaustair of the cooling fan, which constitutes a major limiting factoragainst downsizing or price-reduction of the apparatus. Further,processing speed of electronic devices such as personal computers havebeen drastically improved, and thus the temperature inside the housingtends to rise owing to the location of a circuit board, etc., on whichthe CPU and various drive ICs are mounted. For this reason, it isnecessary to provide a large axial flow fan or dust-proof structure toprevent dust, etc., from entering the set, causing complexity andupsizing of the structure).

Furthermore, the above-described conventional projection type displaydevice has excessive air blowing resistance of the cooling fan caused bysuch a light-shielding member, which requires high-speed drive of thecooling fan to cope with an increased amount of heat generated at thehigh-power light source lamp unit, producing loud noise and interferingwith audiovisual functions.

DISCLOSURE OF THE INVENTION

In view of the above-described problems, it is an object of the presentinvention to provide a fan apparatus, method of manufacturing the fanapparatus, projection type display device, and electronic device,eliminating the need for any light-shielding member and with fewerparts.

A first aspect of the present invention is a fan apparatus comprising:

a rotor section capable of rotating/driving around a predeterminedrotation axis; and

a propeller section attached to said rotor section, having a pluralityof propeller blades arranged in such a way as to substantially shieldlight parallel to said rotation axis.

A second aspect of the present invention is the fan apparatus accordingto the first aspect of the present invention, further comprising a casewhich surrounds the edges of said propeller blades with a predeterminedspace and is left open on the front and back of said propeller blades,

wherein flanges overhang said case in such a way as to shield lightparallel to said rotation axis, which is incident or is to be incidentupon said predetermined space.

A third aspect of the present invention is the fan apparatus accordingto the first aspect of the present invention, further comprising:

a case which surrounds the edges of said propeller blades with apredetermined space and is left open on the front and back of saidpropeller blades; and

a motor support frame attached to said case, for supporting a motor torotate/drive said rotor section,

wherein said motor support frame is provided with a predeterminedlight-shielding member in such a way as to shield light parallel to saidrotation axis, which is incident or is to be incident upon saidpredetermined space.

A fourth aspect of the present invention is the fan apparatus accordingto the first aspect of the present invention, wherein each of saidpropeller blades is constructed of a combination of two or more smallpropeller blades.

A fifth aspect of the present invention is a method of manufacturing thefan apparatus according to the first aspect of the present invention ,comprising:

a fan element molding step of molding a plurality of fan elements madeup of a rotor section element that constitutes said rotor section and apropeller section element that constitutes said propeller section; and

a rotor section element connecting step of connecting rotor sectionelements of said plurality of molded fan elements,

wherein the individual propeller blades of said propeller sectionelement are arranged in such a way as to constitute said propellerblades.

A sixth aspect of the present invention is a projection type displaydevice comprising:

light-emitting means of emitting light;

projecting means of projecting an optical image onto a predeterminedscreen using said emitted light; and

a fan apparatus according to the first aspect of the present inventionfor cooling at least said light-emitting means.

A seventh aspect of the present invention is the projection type displaydevice according to the sixth aspect of the present invention, furthercomprising a housing for housing said light-emitting means, saidprojecting means and said fan apparatus,

wherein the wall section of said housing is provided with an openingthat allows air intake and/or exhaust for said cooling, and

said fan apparatus is placed separately toward the inside of saidhousing by a predetermined distance from said opening.

An eighth aspect of the present invention is an electronic devicecomprising:

a predetermined circuit which operates with heat dissipation; and

a fan apparatus according to a first aspect of the present invention,for cooling at least said predetermined circuits.

A ninth aspect of the present invention is the electronic deviceaccording to the eighth aspect of the present invention, furthercomprising a housing for housing said predetermined circuit and said fanapparatus,

wherein the wall section of said housing is provided with an openingthat allows air intake and/or exhaust for said cooling, and

said fan apparatus is placed separately toward the inside of saidhousing by a predetermined distance from said opening.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1( a) illustrates an axial flow fan according to Embodiment 1 ofthe present invention viewed from the air intake side along the axialdirection;

FIG. 1( b) illustrates an axial flow fan according to Embodiment 1 ofthe present invention viewed from the air exhaust side along the axialdirection;

FIG. 2 is a plan view of a projection type display device according toEmbodiment 2 of the present invention;

FIG. 3 is a right side view of the projection type display deviceaccording to Embodiment 2 of the present invention;

FIG. 4 is a perspective view of an electronic device according toEmbodiment 3 of the present invention;

FIG. 5 illustrates a conventional axial flow fan;

FIG. 6 is a plan view of a conventional projection type display device;

FIG. 7 is a right side view of the conventional projection type displaydevice;

FIG. 8 illustrates a fan apparatus according to the present invention;

FIG. 9( a) illustrates a fan element 400 a of the fan apparatusaccording to the present invention;

FIG. 9( b) illustrates a fan element 400 b of the fan apparatusaccording to the present invention; and

FIG. 10 illustrates a fan apparatus provided with a case 430 of thepresent invention.

DESCRIPTION OF SYMBOLS

-   1 light source lamp unit-   2 irradiation optical unit-   3 liquid crystal panel unit-   4 color combination system unit-   5 projection optical unit-   6 cooling fan-   7 light-shielding member-   8 housing-   9 exhaust opening-   10 housing-   11 motor-   12 propellers-   13 air duct-   101 motor-   102 housing-   103 propeller blades-   104 air duct-   105 stator side of a motor-   201 axial flow fan-   301 housing-   302 heating members-   303 exhaust opening-   304 axial flow fan

BEST MODE FOR CARRYING OUT THE INVENTION

With reference now to the attached drawings, embodiments of the presentinvention will be explained below.

Embodiment 1

First, with reference to mainly FIGS. 1( a) and (b) a configuration ofan axial flow fan of this embodiment will be explained. FIG. 1( a)illustrates an axial flow fan according to Embodiment 1 of the presentinvention viewed from the air intake side along the axial direction andFIG. 1( b) illustrates an axial flow fan according to Embodiment 1 ofthe present invention viewed from the air exhaust side along the axialdirection.

In FIGS. 1( a) and 1(b), the rotation center on the stator side of amotor 101 which is a rotation drive source is fixed to the center of amotor support frame provided in a plurality of spokes withoutinterrupting the air flow, using a housing 102 which serves as thehousing of the fan.

A plurality of propeller blades 103 formed integral with the outerradius side of the rotor which constitutes a rotator of the motor 101provide the means of blowing air. The propeller blades 103 are formed insuch a way that mutually neighboring propeller blades overlap with eachother in a projective view from the axial direction in an area withinthe inner diameter 104A of an air duct 104. This prevents the back sidein the axial direction (that is, the air intake side) from being seenthrough a gap between the mutually neighboring propeller blades 103 anda gap between the air duct 104 and propeller blades 103 from the surfaceside in the axial direction (that is, the air exhaust side).

The air duct 104 is an air duct for the air circulated through rotationof the propeller blades 103 and formed in such a way as to generallyshare the rotation axis of the motor 101 as its axis. The air duct 104is expressed by a dotted line in FIG. 1( a) and a solid line in FIG. 1(b). Furthermore, the inner diameter 104A of the air duct 104 is smallerthan the outer diameter of the rotating propeller blades 103 and anoffset is formed in such a way that it slightly increases toward the airexhaust side to prevent the rotating propeller blades 103 from touchingthe air duct 104.

Further, the means including the rotor of this embodiment corresponds tothe rotor section of the present invention and the means including thepropeller blades 103 corresponds to the propeller section of the presentinvention. Furthermore, the housing 102 corresponds to the case of thepresent invention. The axial flow fan in this embodiment corresponds tothe fan apparatus of the present invention.

Next, an operation of the axial flow fan in this embodiment will beexplained.

The motor 101 held in the center of the motor support frame provided inthe housing 102 is rotated in the direction indicated by an arrow A by asupply voltage.

Furthermore, the plurality of propeller blades 103 formed integral withthe rotor side which serves as the rotator of the motor 101 are alsorotated in the direction indicated by the arrow A.

As a result, a pressure difference is produced at both ends of theintake and exhaust sides of the propeller blades 103 and air is taken infrom the intake side shown in FIG. 1( a). The intake air is led throughthe propeller blades 103, through the inner radius side of the air duct104 formed in the housing 102 and exhausted to the exhaust side shown inFIG. 1( b).

Thus, the axial flow fan of this embodiment includes the motor whichserves as a rotation drive source, a plurality of air blowing means,formed integral with the perimeter on the rotor side of the motor, whichrotates together with the motor and sends air in the axial direction ofthe motor, a housing that forms one body with a circular air duct havingan inner diameter smaller than an external diameter of theabove-described air blowing means and holds the stator side of the motoras one body in such a way that the rotation center of the motor almostaligns with the center of the above-described air duct, characterized inthat the plurality of air blowing means are constructed in such a waythat the plurality of neighboring air blowing means overlap with oneanother with no gap between the air blowing means and air duct in aprojective view from the axial direction of the motor, so that the airintake side cannot generally be seen from the air exhaust side insidethe air duct. Here, the air blowing means used for the above-describedaxial flow fan are shaped as propeller blades of the axial flow fan.

The axial flow fan characterized as shown above, in a configuration witha high degree of freedom without using any light-shielding member ordust-proof member can (1) effectively cool the device without lettingout unnecessary light such as light from the light source lamp unit, (2)prevent dust from entering the set, (3) drastically reduce noise causedby air blowing without deteriorating the cooling performance becausethere is no more air blowing resistance by the light-shielding member ordust-proof member, (4) improve the quality of the set because it can beused as a cooling fan when it is desirable to make the interior of theset invisible to the user, and (5) promote price-reduction ordown-sizing by eliminating the need for the light-shielding member ordust-proof member and thereby reducing the number of parts.

Embodiment 2

First, a configuration of a projection type display device of thisembodiment will be explained mainly with reference to FIGS. 2 and 3.FIG. 2 is a plan view of a projection type display device according toEmbodiment 2 of the present invention and FIG. 3 is a right side view ofa projection type display device according to Embodiment 2 of thepresent invention.

Here, the same means as the means of a conventional projection typedisplay device (see FIGS. 6 and 7) are assigned the same referencenumerals.

FIG. 2 shows a projection type display device provided with a lightsource lamp unit 1, an irradiation optical unit 2 that condenses lightfrom the above-described light source lamp unit 1, three liquid crystalpanel units 3 consisting of R, G and B liquid crystal panels foroptically generating image information from the condensed light, a colorcombination system unit 4 that color-combines the optical information ofthe liquid crystal panel units 3, a projection optical unit 5 thatenlarges and projects the image information onto a screen, a powersupply unit (not shown) which serves as a drive source of the lightsource lamp unit 1 and the electrical system of the entire apparatus andan axial flow fan 201 that exhausts air for the light source lamp unit 1and the entire apparatus.

The projection type display device of this embodiment uses the axialflow fan 201 having the same configuration as that of the axial flow fanexplained in the above-described Embodiment 1 as the cooling fanintended to cool the light source lamp unit 1 and the entire apparatus.More specifically, the axial flow fan 201 is an axial flow fan forcooling the light source lamp unit that takes in and exhausts a hightemperature atmosphere around the light source lamp unit 1, therebyappropriately cools and adjusts temperature of a high temperaturesection of the light source lamp unit 1.

Here, since the axial flow fan 201 is placed separated (indented) towardthe inside of the housing 8 by a predetermined distance from an exhaustopening 9, a light-shielding characteristic in a direction diagonal tothe rotation axis of a motor of the axial flow fan 201 is improved.

By the way, the means including the light source lamp unit 1 correspondsto the light-emitting means of the present invention, the meansincluding the projection optical unit 5 corresponds to the projectingmeans of the present invention and the axial flow fan 201 corresponds tothe fan apparatus of the present invention. Furthermore, the housing 8corresponds to the housing of the present invention and the exhaustopening 9 corresponds to the opening of the present invention.Furthermore, the projection type display device of this embodimentcorresponds to the projection type display device of the presentinvention.

Then, an operation of the projection type display device of thisembodiment will be explained.

The projection type display device of this embodiment (1) leads theoutgoing light from the light source lamp unit 1 to the three liquidcrystal panel units 3 each consisting of components R, G and B, whichare light bulbs, using the irradiation optical unit 2 to decompose theoutgoing light into the color components R, G and B, and forms imageinformation and (2) combines the R, G and B components at the colorcombination system unit 4 and then projects the combined light onto ascreen, etc., using the projection optical unit 5.

As in the case of aforementioned Embodiment 1, the entire set is cooledand the light source lamp unit 1 is adjusted to an optimum temperatureby exhausting the high temperature atmosphere of the light source lampunit 1 through the rotation of the propeller blades of the axial flowfan 201 formed in such a way that mutually neighboring propeller bladesoverlap with each other in a projective view from the axial direction.

Since the neighboring propeller blades overlap with each other in aprojective view from the axial direction, the light-shielding member toprevent unnecessary light from the light source lamp unit 1 from leakingout of the set is no longer necessary. Furthermore, it is possible tocool the light source lamp unit and its periphery at high efficiencywithout allowing the unnecessary light components of the light sourcelamp unit to leak out of the apparatus.

Furthermore, cooling which would be attained through high-speed rotationof the exhaust fan can be realized through low-speed rotation. Thismakes it possible to reduce NZ noise of the fan (blade passing frequencyN*Z which is defined as the product of the number N of revolutions ofthe fan and the number Z of fan blades is a frequency indicating thecomponent of interference sound generated by rotation of the fan) to anextremely low level and has an advantage of being able to reduce noiseof the entire apparatus to an extremely low level without deterioratingthe cooling performance. Furthermore, since light from the light sourcelamp unit hardly leaks out of the set, it is possible to realize aprojection type display device of high quality.

Of course, applying conduction processing to the air blowing means ofthe axial flow fan 201 drastically reduces the possibility that noise asunnecessary radiation leaks outward.

Thus, the projection type display device of this embodiment is aprojection type display device provided with a light source, light bulbsthat receive outgoing light from the light source and form an opticalimage, a projection lens that receives the outgoing light from the lightbulbs and projects the optical image onto a screen and cooling means ofcooling the light source and periphery of the light source,characterized in that the aforementioned axial flow fan is used as thecooling means of cooling the light source and periphery of the lightsource.

The projection type display device characterized as shown above in aconfiguration with a high degree of freedom without using anylight-shielding member or dust-proof member can (1) effectively cool thedevice without letting out unnecessary light such as light from thelight source lamp unit, (2) prevent dust from entering the set, (3)drastically reduce noise caused by air blowing without deteriorating thecooling performance because there is no more air blowing resistance bythe light-shielding member or dust-proof member, (4) improve the qualityof the set because it can be used as a cooling fan when it is desirableto make the interior of the set invisible to the user, and (5) promoteprice-reduction or down-sizing by eliminating the need for thelight-shielding member or dust-proof member and thereby reducing thenumber of parts.

Embodiment 3

First, a configuration of an electronic device of this embodiment willbe explained mainly with reference to FIG. 4. FIG. 4, is a perspectiveview of the electronic device according to Embodiment 3 of the presentinvention.

A housing 301 is a housing of an electronic device such as a personalcomputer.

Inside the housing 301 is one or a plurality of heating members 302having such a large amount of heat generated that requires cooling atleast by forced air cooling. For example, a circuit board with a driveIC mounted and CPU, etc., correspond to this heating material.

The housing 301 is provided with an air intake opening (not shown) totake in air outside the housing 301 and an exhaust opening 303 toexhaust a high temperature atmosphere from the interior of the housing301.

An axial flow fan 304 is an axial flow fan for forced air cooling havingthe same configuration as that of the axial flow fan explained in theabove-described Embodiment 1.

The exhaust opening 303 which serves as an opening to circulate air toventilate or exhaust a high temperature atmosphere is formed inside thehousing 301 and an axial flow fan 304 is placed inside the housing 301facing the exhaust opening 303.

Here, the axial flow fan 304 is placed inside the housing 301 separated(indented) by a predetermined distance from the exhaust opening 303,which improves the light-shielding characteristic in a directiondiagonal to the rotation axis of the motor of the axial flow fan 304.

Of course, it is also possible to provide an air intake opening to takein air outside the housing into the housing 301 and set the axial flowfan 304 inside the housing 301 facing the air intake opening.

Further, the means including the heating member 302 corresponds to apredetermined circuit of the present invention, the axial flow fan 304corresponds to the fan apparatus of the present invention. Furthermore,the housing 301 corresponds to the housing of the present invention andthe exhaust opening 303 corresponds to the opening of the presentinvention. Furthermore, the electronic device of this embodimentcorresponds to the electronic device of the present invention.

Then, an operation of the electronic device of this embodiment will beexplained.

Cooling of the heating member 302 installed inside is realized throughthe function and operation of the electronic device.

At this time, the axial flow fan 304 is driven to exhaust a hightemperature atmosphere inside and cool the interior of the housing 301and the heating member 302 and maintain them in a desired state.

Since the axial flow fan 304 is placed inside the housing 301 facing theexhaust opening 303, the light-shielding characteristic in a diagonaldirection is improved as described above, making the interior of thehousing 301 hardly visible from the outside through the exhaust opening303.

Thus, by not only preventing dust, etc., from entering the electronicdevice but also making the interior invisible to the user, thisembodiment has an advantage of eliminating internal wiring or anyblinder material, etc.

Furthermore, since the mutually neighboring propeller blades of theaxial flow fan 304 are formed in such a way as to overlap with eachother in a projective view from the axial direction, even if alight-emitting member is provided inside, no light will leak outward.

Of course, applying conductive processing to the air blowing means ofthe axial flow fan 304 reduces the possibility to an extremely smalllevel that noise as unnecessary radiation leaks outward.

By the way, the light transmission type liquid crystal panel units 3 ofthe projection type display device are light bulbs in theabove-described embodiment, but they can also be light bulbs forming anoptical image as the optical feature.

Furthermore, the electronic device in the above-described embodiment isa personal computer, but it can also be other electronic devicesrequiring cooling such as audio products and audiovisual devices.

As described above, the electronic device of this embodiment is providedwith a housing including an air intake opening and air exhaust openingfor forced air-cooling of a heating member to a desired state andcooling means of forced air-cooling at least at either the air intakeopening or air exhaust opening inside the housing, characterized in thatthe aforementioned axial flow fan is used as the cooling means.

The electronic device having such features in a configuration withoutusing any light-shielding member or dust-proof member, with a highdegree of freedom can (1) efficiently cool the device without leakingunnecessary light from the light source lamp unit, etc., (2) preventdust from entering the set, (3) drastically reduce noise caused byblowing without deteriorating the cooling performance because there isno more air blowing resistance due to the light-shielding member ordust-proof member, (4) improve the quality of the set because it can beused as a cooling fan when it is desirable to make the interior of theset invisible to the user, and (5) promote price-reduction ordown-sizing by eliminating the need for the light-shielding member ordust-proof member and thereby reducing the number of parts.

So far, Embodiments 1 to 3 have been explained in detail.

By the way, each propeller blade may also be constructed of acombination of two or more small propeller blades. For example, as shownin FIG. 8, which illustrates the fan apparatus of the present invention,the fan apparatus provided with (1) a rotor section 410 that can berotated/driven around a predetermined rotation axis (in the directionperpendicular to the plane of this figure sheet), (2) a propellersection 420 attached to the rotor section 410, having propeller blades421 to 428 arranged in such a way as to substantially shield lightparallel to the rotation axis, is a specific example of the fanapparatus of the present invention. Here, for example, the propellerblade 421 has a configuration combining two small propeller blades 421 aand 421 b (to be easily understandable, the two small propeller bladesare expressed in different display patterns).

As shown in FIG. 9( a) which illustrates a fan element 400 a of the fanapparatus of the present invention and FIG. 9( b) which illustrates afan element 400 b of the fan apparatus of the present invention, themethod of manufacturing the fan apparatus (see FIG. 8) including (1) afan element molding step of molding a fan element 400 a made up of arotor section element 410 a that constitutes the rotor section 410 and apropeller section element 420 a that constitutes the propeller section420, and a fan element 400 b made up of a rotor section element 410 bthat constitutes the rotor section 410 and a propeller section element420 b that constitutes the propeller section element 420 and (2) a rotorsection element connecting step of connecting the rotor section elements410 a and 410 b of the molded fan elements 400 a and 400 b,characterized in that when a connection is made, the individual smallerpropeller blades of the propeller section elements 420 a and 420 b arearranged in such a way as to constitute the propeller blades 421 to 428,is a specific example of the method of manufacturing the fan apparatusof the present invention. Here, for example, the small propeller blades421 a and 421 b making up the propeller blade 421 may also be connectedusing an adhesive or arranged without being connected in such a way thatthey overlap with each other when viewed from the direction of therotation axis. Since the propeller section elements 420 a and 420 b haveno small propeller blades overlapping with each other viewed from therotation axis direction, it facilitates metal molding.

Further, as shown in FIG. 10 which illustrates a fan apparatus providedwith a case 430 of the present invention, the fan apparatus providedwith the case 430 with the edges of the propeller blades surrounded witha predetermined space S and the front and back of the propeller bladesleft open, characterized in that (1) flanges (not shown) overhang on thefront and/or back of the propeller blades in such a way as to shieldlight parallel to the rotation axis, which is incident or is to beincident upon the predetermined space S or (2) a motor support frame(not shown) attached to the case 430, for supporting a motor torotate/drive the rotor section, is further provided and the motorsupport frame is provided with a predetermined light-shielding member(not shown) on the front and/or back of the propeller blades, in such away as to shield light parallel to the rotation axis, which is incidentor is to be incident upon the predetermined space S, is a specificexample of the fan apparatus of the present invention. By shielding thepredetermined space S using the flanges and light-shielding member, itis possible to suppress leakage of unnecessary light from inside theapparatus.

As is apparent from the above explanations, the present invention has anadvantage of being able to eliminate the need for any light-shieldingmember and reducing the number of parts in a fan apparatus.

1. A fan apparatus comprising: a rotor section capable ofrotating/driving around a predetermined rotation axis; a propellersection attached to said rotor section, having a plurality of propellerblades; and a case which is housing the plurality of propeller blades;wherein the case having an air duct, the air duct having an opening in adirection of the rotation axis; and the plurality of propeller bladesare constructed with no gap between the mutually neighboring propellerblades and between the propeller blades and the opening in a projectiveview from the direction of the rotation axis.
 2. The fan apparatusaccording to claim 1, wherein a motor support frame attached to saidcase, for supporting a motor to rotate/drive said rotor section.
 3. Thefan apparatus according to claim 1, wherein each of said propellerblades is constructed of a combination of two or more small propellerblades.
 4. A method of manufacturing the fan apparatus according toclaim 1, comprising: a fan element molding step of molding a pluralityof fan elements made up of a rotor section element that constitutes saidrotor section and a propeller section element that constitutes saidpropeller section; and a rotor section element connecting step ofconnecting rotor section elements of said plurality of molded fanelements, wherein the individual propeller blades of said propellersection element are arranged in such a way as to constitute saidpropeller blades.
 5. A projection type display device comprising:light-emitting means of emitting light; projecting means of projectingan optical image onto a predetermined screen using said emitted light;and said fan apparatus according to claim 1 for cooling at least saidlight-emitting means.
 6. The projection type display device according toclaim 5, further comprising a housing for housing said light-emittingmeans, said projecting means and said fan apparatus, wherein a wallsection of said housing is provided with an opening that allows airintake and/or exhaust for said cooling, and said fan apparatus is placedseparately toward the inside of said housing by a predetermined distancefrom said opening.
 7. An electronic device comprising: a predeterminedcircuit which operates with heat dissipation; and said fan apparatusaccording to claim 1 for cooling at least said predetermined circuit. 8.The electronic device according to claim 7, further comprising a housingfor housing said predetermined circuit and said fan apparatus, wherein awall section of said housing is provided with an opening that allows airintake and/or exhaust for said cooling, and said fan apparatus is placedseparately toward the inside of said housing by a predetermined distancefrom said opening.